A known technique for measuring a biological sample is described in Patent Document 1 mentioned below. In Patent Document 1, a sensor chip for measuring the temperature of a blood sample is provided. A predetermined voltage is applied to the working electrode and the counter electrode of the sensor chip to measure the temperature of the blood sample. The predetermined voltage is selected to be a value that has little effect on the change in, for example, concentration of glucose. Furthermore, in this sensor chip, a voltage is applied to the same electrodes to measure, for example, the concentration of glucose of a blood sample.